Grader screen



March 6, 1934. w TH 1,949,697

GRADER SCREEN Filed April 27, 1931 :E I 5 l q,

IN VEN TOR. Home 710 14 501/ TH A TORNEKS.

Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE pillar Tractor Co., poraticn of California San Leandro, Califi, a cor- Application April 27, 1931, Serial No. 533,216

2 Claims.

This invention relates to grader screens and particularly to such a screen in a threshing machine for cleaning grain after it is threshed.

The objects of the invention are: first, to provide an improved grain grader; second, to provide a grader screen with an agitator.

Description of figures Fig. l is a sectional view of a grader screen 10 provided with an agitator.

Fig. 2 is a sectional view of a screen provided with another form of agitator.

Fig. 3 is a detailed view of the agitator on line 3-3 of Fig. 2.

Description of mechanism Grain is delivered from the threshing mechanism to an auger l rotated by shaft 11 driven by sprocket 12 from the driving mechanism of the threshing machine. The grain is carried in the direction of arrows 13 by auger and deposited in rotating screen 14. Spiral baffle 15 is supported by arm 16 from shaft 11. This baffle serves to feed the grain as the screen rotates.

The kernels drop out of the bottom of the screen, as indicated by arrows 1'7, and the chaff and clods are expelled at the end, as indicated by arrows l8, and may be returned to the threshing mechanism. Shaft 11 is suitably supported in bearings 19, 20, secured to the side walls of the housing in which the screen is located. Screen 14 is supported by head 22; and bafiie 15 is supported by arm 16. The hubs of head 22 and arm 16 are provided with bushings on shaft 11 so that the screen can move freely relatively to the shaft. Collar 23 is connected by bolt 24 to shaft 11, and one end of spring 25 is secured to bolt 24. The other end of spring 25 is connected by screw 26 to the hub of head 22. Head 22 has a serrated flange 27 forming a scalloped cam with which roller 28 engages. Roller 28 is journaled on pin 29 supported in bracket 30 secured to the housing. As shaft 11 is rotated, the screen is driven through the spring connection 25, and due to the contact of roller 28 with the serrations of flange 27, the screen will be reciprocated axially as it is rotated. The rotative movement of the screen will also be an alternate acceleration and deceleration. As the screen is rotated, it is jerked and shaken, thereby facilitating passage of the grain kernels through the screen, and preventing their clogging at the pores of the screen.

In the embodiment illustrated in Fig. 2, screen 14 is supported on heads 31, 32, the hubs of which are provided with bearings on shaft 11. The drive is transmitted from the shaft 11 through the spring 25 to head 31, as in the first embodiment. However, the head 31 is provided with a flange 33, the periphery of which is provided with serrations or humps 34 to form ascalloped cam (Fig. 3). The roller 35 journaled on an arm 36 pivoted at 37 in bracket 38 secured to the housing, is maintained in contact with the serrated periphery of flange 33 by a spring 39. By this construction, the screen movement is an alternate acceleration 5 and deceleration, as the jerking and jarring of the screen facilitates the passage of the grain kernels through the pores of the screen.

I, therefore, claim as my invention:

1. In a machine of the class described, a cylin- 7o drical screen, a rotatable drive shaft passing axially through said screen, members secured to said screen and being freely journaled about said shaft to support the screen for axial reciprocation along said shaft, a cam having an interrupted cam sur- 745 face fixedly secured for rotation with said screen, the plane of said surface extending transversely with respect to the axis of said shaft, a cam roller journaled to rotate about an axis transverse to said shaft axis and adapted to contact said cam so surface, and coiled spring means surrounding said shaft and secured to both the screen and the shaft to hold the cam surface against the roller, whereby when the shaft is rotated the screen is caused to reciprocate axially and to have a jerking motion.

2. In a machine of the class described, a rotatable screen, a rotatable drive shaft passing axially through said screen, members secured to said screen and being freely j ournaled about said shaft, 9 one of said members being a perforated head member positioned adjacent an end of the screen, coiled spring means surrounding said shaft and secured to both the head member and the shaft to provide a flexible driving connection from the 5 shaft to the screen, a cam having an interrupted cam surface rigid with the head member, and a cam roller acting against said cam surface to cause said screen to have a jerking motion during rotation.

HORATIO W. SMITH. 

